In long term evolution (LTE), various wireless technologies have been examined to realize larger capacity of systems, further acceleration of data transmission speeds, further low delay of wireless sections, and the like.
In LTE, a technology referred to as coordinated multipoint (CoMP) in which a plurality of base stations cooperate to be able to transmit and receive wireless signals is realized. In CoMP, when a plurality of base stations cooperate to transmit and receive downlink signals, it is possible to improve reception quality at a cell end at which a plurality of cells overlap each other. An example of cooperation transmission in LTE is illustrated in FIG. 1.